Battery recycling by reduction and carbonylation

Abstract

The present invention relates to a method for recovering transition metals from battery materials, the method comprising the steps of: (1.1) providing a battery material comprising nickel oxide and / or cobalt oxide compounds; (1.1) heating the battery material to greater than 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls comprising nickel carbonyl and / or cobalt carbonyl-containing compounds; and (3.1) separating the volatile carbonyls from the solid carbonyl residue by evaporation.

Description

[Technical Field]

[0001] The present invention relates to a method for recovering transition metals from battery materials, the method comprising the steps of: (1.1) providing a battery material comprising nickel oxide and / or cobalt oxide compounds; (1.1) heating the battery material to greater than 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls comprising nickel carbonyl and / or cobalt carbonyl-containing compounds; and (3.1) separating the volatile carbonyls from the solid carbonyl residue by evaporation. [Background technology]

[0002] The lifespan of batteries, especially lithium-ion batteries, is not without limitations. Therefore, it is expected that the number of used batteries will continue to increase. Because batteries contain important transition metals, such as, but not limited to, cobalt and nickel, and also lithium, used batteries can form a valuable source of raw materials for new generation batteries. For this reason, increasing research activities are being conducted with the aim of recycling transition metals, and optionally even lithium, from used lithium-ion batteries.

[0003] Various methods have been found to recover the raw materials. One method is based on the smelting of the corresponding battery scrap and subsequent hydrometallurgical processing of the metal alloys obtained from the smelting process. Another method is the direct hydrometallurgical processing of the battery scrap material. Such hydrometallurgical processes yield the transition metals, for example, individually as hydroxides, or as aqueous solutions or in precipitated form already in the desired stoichiometry for making new cathode active materials. Summary of the Invention [Problem to be solved by the invention]

[0004] The process of the present invention pursues several objectives: easy, cheap, fast and / or efficient recovery of transition metals such as nickel and / or cobalt; avoiding the introduction of new impurities into the process that would require additional purification steps. [Means for solving the problem]

[0005] The object is to provide a method for recovering transition metals from battery materials, comprising: (0.1) providing a battery material comprising a nickel oxide and / or cobalt oxide compound; (1.1) heating the battery material to above 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls, including nickel carbonyl and / or cobalt carbonyl-containing compounds; and (3.1) Separating volatile carbonyls from the solid carbonylation residue by evaporation The method is realized by the method including:

[0006] In a preferred embodiment, the method for recovering transition metals from battery materials comprises: (0.1) providing a battery material, such as a finished battery, a mechanically processed waste battery, or battery scrap, comprising a nickel oxide and / or a cobalt oxide compound; (0.2) optionally washing the battery material with an organic solvent to remove the organic electrolyte and polymer binder; (0.3) optionally washing the battery material with an aqueous medium; (0.4) optionally subjecting the battery material to solid-solid separation, such as flotation, electronic sorting, sieving, or magnetic separation, to remove solids, such as carbon, polymers, or magnetic materials; (0.5) optionally, heating the battery materials up to 350°C to evaporate organic components of the electrolyte; (1.1) heating the battery material to above 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (1.2) optionally subjecting the reduced material to dry solid-solid separation, such as electronic sorting, sieving, or magnetic separation, to remove solids such as carbon, polymers, or magnetic materials; (1.3) optionally treating the reduced material with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material, optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material, and optionally subjecting the insoluble material to solid-solid separation to remove solids such as carbon, polymers, or magnetic material or insoluble lithium salts; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, at a temperature of 30-300°C and a partial pressure of 1-300 bar to produce a solid carbonyl residue and volatile carbonyls selected from nickel carbonyl and / or cobalt carbonyl containing compounds; (3.1) separating volatile carbonyls from the solid carbonylation residue by evaporation; (3.2) optionally purifying the separated volatile carbonyls by adsorption, condensation, distillation or vaporization; (3.3) optionally decomposing solid non-volatile metal carbonyls in the solid carbonylation residue; (3.4) optionally subjecting the solid carbonylation residue to dry solid-solid separation, such as electronic sorting, sieving or magnetic separation, to remove solids such as carbon, polymers or magnetic materials; (3.5) optionally treating the solid carbonylation residue with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material, optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material, and optionally subjecting the insoluble material to solid-solid separation to remove solids such as carbon, polymers, magnetic material or insoluble lithium salts; (4.1) optionally, decomposing volatile carbonyls to produce nickel and / or cobalt in elemental form or as salts; and (4.2) Optionally, further purifying the nickel and / or cobalt Includes:

[0007] In another preferred form, the method comprises at least one of steps (0.2), (0.3), (0.4), (0.5), (1.2), (1.3), (3.2), (3.3), (3.4), (3.5) and (4.2).

[0008] In another more preferred embodiment, the method comprises at least one of steps (0.1), (1.1), (2.1), (3.1), (3.5), and (4.1). DETAILED DESCRIPTION OF THE INVENTION

[0009] Recovering transition metals from batteries, such as lithium-ion batteries, typically means that the transition metals (e.g., nickel, cobalt, and / or manganese) and optionally higher value elements (e.g., lithium and / or carbon) can be at least partially recovered, typically at least 10, 20, 30, 40, 50, 60, 70, 80, 90, 95%, or 99% by weight each. Preferably, at least nickel, cobalt, and / or lithium are recovered by the present method.

[0010] The transition metals and optionally higher value elements are recovered from batteries, preferably lithium ion batteries, such as used or new batteries, parts of batteries, cathode active materials thereof of non-standard materials (e.g., not meeting specifications and requirements), or manufacturing waste from battery manufacturing.

[0011] Step (0) - Preparation and manufacturing of battery materials Step (0.1) is a step of preparing a battery material, such as a finished battery, a mechanically processed waste battery, or battery scrap, containing a nickel oxide and / or a cobalt oxide compound.

[0012] The battery material is a material derived from a battery, preferably a lithium-ion battery. For safety reasons, such batteries are usually fully discharged, or else may be short-circuited, which may pose a risk of fire and explosion. Such lithium-ion batteries can be disassembled and crushed, for example, by a hammer mill, or chopped into small pieces by an industrial shredder. This type of mechanical processing can produce active materials for battery electrodes, which contain transition metal materials that may have regular shapes, but usually have irregular shapes. However, it is preferable to remove as much as possible light fragments, such as organic plastics and housing parts made of aluminum or copper foil, for example, by forced gas flow, air separation, or classification.

[0013] In one form, the battery materials are present in the form of a finished battery.

[0014] Battery materials are often derived from battery scrap, such as lithium-ion batteries. Such battery scrap can be derived from used batteries or manufacturing waste, e.g., off-spec material. In a preferred embodiment, the transition metal material is obtained from mechanically processed battery scrap, e.g., battery scrap processed in a hammer mill or industrial shredder. Such transition metal material can have an average particle size (D50) ranging from 1 μm to 1 cm, preferably 1 to 1000 μm, and particularly 3 to 500 μm. Larger portions of the battery scrap, such as housings, wires, and electrode support films, are typically mechanically separated to allow for broad exclusion of the corresponding materials from the transition metal material used in the present method.

[0015] Preferably, the battery materials are present in the form of finished batteries or machined battery scrap.

[0016] The battery materials can include lithium and its compounds, carbon in a conductive form (e.g., graphite, soot, and graphene), solvents used in electrolytes (e.g., organic carbonates such as diethyl carbonate), aluminum and its compounds (e.g., alumina), iron and iron compounds, zinc and zinc compounds, silicon and silicon compounds (e.g., silica, silicate, and silicon oxide SiO y (0 < y < 2)), tin, silicon-tin alloys, and organic polymers (polyethylene, polypropylene, and fluorinated polymers, e.g., polyvinylidene fluoride, etc.), fluorides, and compounds of phosphorus (e.g., those that can be derived from the liquid electrolyte in widely used LiPF6 and the products resulting from the hydrolysis of LiPF6).

[0017] The battery materials can contain nickel oxide at 1 to 61% by mass, preferably 2 to 30% by mass, particularly 4 to 18% by mass.

[0018] The battery materials can contain cobalt oxide at 1 to 61% by mass, preferably 2 to 30% by mass, particularly 4 to 20% by mass.

[0019] The battery materials can contain manganese, either as a metal or in one or more forms of its compounds, at 1 to 59% by mass, preferably 2 to 30% by mass, particularly 4 to 20% by mass.

[0020] The battery materials can contain lithium, either as a metal or in one or more forms of its compounds, at 0.5 to 12% by mass, preferably 1 to 8% by mass, particularly 1 to 5% by mass.

[0021] The battery materials can contain aluminum, either as a metal or in one or more forms of its compounds, at 100 ppm to 15% by mass.

[0022] The battery materials can contain copper, either as a metal or in one or more forms of its compounds, at 20 ppm to 3% by mass.

[0023] The battery material may contain iron as a metal or alloy, or in one or more forms of its compounds, in an amount of 100 ppm to 5% by mass. The transition metal material may contain zinc as a metal or alloy, or in one or more forms of its compounds, in an amount of 20 ppm to 2% by mass. The battery material may contain zirconium as a metal or alloy, or in one or more forms of its compounds, in an amount of 20 ppm to 2% by mass. The battery material may contain tungsten as a metal or alloy, or in one or more forms of its compounds, in an amount of 20 ppm to 2% by mass. The battery material may contain fluorine in an amount of 0.5% to 10% by mass, calculated as the total of inorganic fluorides in one or more of organic fluorine or additives bonded to the organic polymer and their inorganic fluorides. The battery material may contain phosphorus in an amount of 0.2% to 10% by mass. Phosphorus may occur in one or more inorganic compounds.

[0024] The battery material usually contains cobalt and, in most cases, at least one of nickel and manganese. Examples of such transition metal materials may be based on LiCoO2, lithium nickel cobalt manganese oxide ("NCM") or lithium nickel cobalt aluminum oxide ("NCA") or mixtures thereof.

[0025] An example of a layered nickel cobalt manganese oxide is a compound of the general formula Li 1+x (Ni a Co b Mn c M 1 d ) 1-x O2, where M 1 is selected from Mg, Ca, Ba, Al, Ti, Zr, Zn, Mo, V and Fe, and the further variables are defined as follows: 0≦x≦0.2, 0≦a≦0.8, 0.05≦b≦1, preferably 0.05 < b≦0.5, 0≦c≦0.6, 0≦d≦0.1 and a + b + c + d = 1. A preferred layered nickel-cobalt-manganese oxide is M 1is selected from Ca, Mg, Zr, Al and Ba, and the further variables are as defined above. A preferred layered nickel-cobalt-manganese oxide is (1+x) [Ni 0.33 Co 0.33 Mn 0.33 ] (1-x) O2, Li (1+x) [Ni 0.5 Co 0.2 Mn 0.3 ] (1-x) O2, Li (1+x) [Ni 0.6 Co 0.2 Mn 0.2 ] (1-x) O2, Li (1+x) [Ni 0.7 Co 0.2 Mn 0.3 ] (1-x) O2 and Li (1+x) [Ni 0.8 Co 0.1 Mn 0.1 ] (1-x) O2, and each x is as defined above.

[0026] Examples of lithiated nickel cobalt aluminum oxides have the general formula Li[Ni h Co i Al j ]O 2+r wherein h is in the range of 0.8 to 0.90, i is in the range of 0.15 to 0.19, j is in the range of 0.01 to 0.05, and r is in the range of 0 to 0.4.

[0027] Step (0.2) is an optional step of washing the battery material with an organic solvent to remove the organic electrolyte or polymer binder. When the battery material is present as machined battery scrap, step (0.2) is preferably used to assist in dissolving and separating the polymer binder used to bind the transition metal oxide to the current collector film or, for example, to bind graphite to the current collector film. Suitable solvents are N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N-ethylpyrrolidone, and dimethyl sulfoxide in pure form, as a mixture of at least two of the following, or as a mixture with 1 to 99% by weight of water.

[0028] Step (0.3) is a step of optionally washing the battery material with an aqueous medium. When the battery material is present as mechanically processed battery scrap, step (0.3) is preferably used to assist in the removal of liquid and water-soluble impurities from the battery material. The washing step can be improved, for example, by grinding in a ball mill or an agitated ball mill. The washed battery material can be recovered by a solid-liquid separation step, for example, filtration or centrifugation, or any type of precipitation and decantation. A flocculant, for example, polyacrylate, may be added to support the recovery of fine particles of such solid transition metal material.

[0029] Step (0.4) is a step of optionally subjecting the battery material to solid-solid separation, such as flotation, electronic sorting, sieving, or magnetic separation, to remove solids such as carbon, polymers, or magnetic materials, or a combination of at least two of these operations. When the battery material is present as mechanically processed battery scrap, step (0.4) is preferably used to assist in the removal of carbon and / or polymer materials. Examples of solid-solid separation steps include classification, density separation, flotation, heavy medium separation, magnetic separation, and electronic sorting. Typically, the aqueous slurry obtained before step (0.4) may be subjected to solid-solid separation, except for electronic sorting, which is performed under dry conditions. Solid-solid separation steps often serve to separate hydrophobic, insoluble components such as carbon and polymers from metal or metal oxide components.

[0030] The solid-solid separation step may be carried out by mechanical, column or air flotation, or hybrid flotation. Collector compounds are added to the slurry to make the hydrophobic components even more hydrophobic. Suitable collector compounds for carbon and polymer materials are hydrocarbons or fatty alcohols, introduced in amounts of 1 g to 50 kg per ton of transition metal material.

[0031] It is also possible to perform flotation in the reverse sense, i.e., converting originally hydrophilic components into strongly hydrophobic components using special collecting substances, such as fatty alcohol sulfates or ester quats. Direct flotation using a hydrocarbon collector is preferred. To improve the selectivity of flotation for carbon and polymeric material particles, inhibitors can be added to reduce the amount of entrained metal and metal oxide components in the foam phase. Potential inhibitors may be acids or bases to control the pH to a value in the range of 3 to 9, or even ionic components that can adsorb to the hydrophilic components. To improve the efficiency of flotation, it may be advantageous to add carrier particles that form agglomerates with the hydrophobic target particles under flotation conditions.

[0032] The magnetic or magnetizable metal or metal oxide components may be separated by magnetic separation using low-, medium-, or high-intensity magnetic separation devices, depending on the magnetic susceptibility of the magnetizable components. Similarly, magnetic carrier particles may be added. Such magnetic carrier particles may form agglomerates with the target particles, thereby allowing non-magnetic materials to also be removed by the magnetic separation technique. Preferably, the magnetic carrier particles may be reused within the separation process.

[0033] The solid-solid separation step typically results in at least two fractions of solid material present as a slurry: one containing primarily cobalt- and nickel-containing battery materials, and one containing primarily carbon-based and polymer battery components. The first fraction can then be subjected to step (1.1), while the second fraction may be further processed to recover the various components, i.e., carbon-based and polymeric materials.

[0034] Step (0.5) is optionally a step of heating the battery material up to 350°C to evaporate organic components of the electrolyte and decompose the polymer binder components. When the battery material is present as machined battery scrap, step (0.5) is preferably used to assist in the evaporation of residual solvent from the battery electrolyte. This heat treatment is preferably performed instead of the optional steps (0.2) and (0.3).

[0035] Step (1) - Reduction and post-treatment of battery materials Step (1.1) is the heating of the battery material above 350° C. to produce a reduced material containing nickel and / or cobalt in elemental form.

[0036] The battery material heated in step (1.1) can be obtained from steps (0.1), (0.2), (0.3), (0.4) or (0.5).

[0037] The battery material is usually heated to a temperature in the range of 350 to 900°C, preferably 350 to 600°C, and more preferably 350 to 500°C.

[0038] The duration of heating can be in the range of 10 minutes to 30 hours, preferably 20 minutes to 8 hours, and more preferably 30 minutes to 4 hours.

[0039] After heating, the reduced material can be cooled, for example, to room temperature or to a temperature somewhat above room temperature, for example, 25-90°C.

[0040] Step (1.1) may be carried out in the presence of lime, quartz or silicate, with lime being preferred. The lime can be selected from slaked lime and quicklime, i.e., calcium oxide. Typically, with reference to the battery material, 2 to 40% by weight of lime, quartz or silicate may be present.

[0041] Step (1.1) is preferably carried out by heating the battery material in an inert atmosphere, a hydrogen atmosphere, or an oxygen atmosphere, and more preferably by heating the battery material to a temperature of 350 to 900°C in an inert atmosphere, a hydrogen atmosphere, or an oxygen atmosphere.

[0042] The hydrogen atmosphere can contain 0.1% to 100% by volume of hydrogen. Preferably, the hydrogen atmosphere contains 3% to 100% by volume of hydrogen, with the remainder being a non-oxidizing gas, preferably nitrogen, argon, steam, carbon monoxide, carbon dioxide, or a mixture of at least two of these gases. Preferred non-oxidizing gases are nitrogen and steam, and mixtures of nitrogen and steam. The concentration of hydrogen in the reducing atmosphere and the reaction time are independent of each other. Typically, a lower concentration of hydrogen requires a longer reduction time, and vice versa.

[0043] The hydrogen atmosphere is applied at a total pressure of 0.1 to 300 bar, preferably 1 to 100 bar, most preferably at ambient pressure of 1 bar or only slightly above a maximum of 5 bar.

[0044] Heating may be carried out in any type of oven that allows the introduction of different gases. These ovens may be operated batchwise or continuously. Preferred ovens are rotary kilns and fluidized bed reactors. These reactors may also be operated continuously. Different gas compositions may be applied to continuous ovens or kilns or to successive sections of a kiln. In the latter case, the gases are introduced in such a way that no mixing of the reactive gases can occur.

[0045] The inert atmosphere may contain nitrogen or a noble gas, preferably nitrogen. The nickel oxide and / or cobalt oxide may be reduced under the inert atmosphere by carbonaceous or organic materials typically derived from the battery or its decomposition products.

[0046] The oxygen atmosphere can contain a certain amount of oxygen, for example, 2 to 10% by volume. In one embodiment, the oxygen atmosphere is air. Nickel oxide and / or cobalt oxide may be reduced in the oxygen atmosphere by carbonaceous or organic materials normally present in batteries, or a reducing atmosphere may be formed by partial combustion in the oxygen atmosphere.

[0047] Alternatively, for example, if volatile organic compounds are present in a feed that is stripped in an inert atmosphere, the composition of the atmosphere may be changed and then the atmosphere may be changed to an oxygen atmosphere.

[0048] Alternatively, the atmosphere may contain, for example, steam under an inert atmosphere containing water in gaseous form, or air containing water in gaseous form.

[0049] In one embodiment, the reduction conditions in step (1.1) are selected such that at least a portion of the battery material contains a paramagnetic, ferromagnetic, or ferrimagnetic component that can be separated by application of a magnetic field, such as in step (1.2). Preferably, the ferromagnetic or ferrimagnetic component is formed from at least a partial reduction of the battery material.

[0050] The nickel oxide and / or cobalt oxide may be reduced in step (1.1) to elemental nickel and / or cobalt in an amount of at least 50, 60, 70, 80, 90 or 95% by weight.

[0051] Heating can be carried out in externally heated ovens, such as electrically heated ovens and fluidized bed reactors, or in ovens with internal combustion, such as rotary kilns. Heat treatment can also be carried out in a vacuum oven.

[0052] The heat treatment can be carried out in a wide pressure range from 0.001 bar to 100 bar. It is preferred to carry out the heat treatment at ambient pressure or below, but slightly above 1 bar.

[0053] In one embodiment, heating can occur in a smelting oven to produce an alloy containing nickel and / or cobalt metals, as well as slag material. Typically, the feed material is pelletized and premixed with slag to form additives and fluxes (e.g., soda, potash, lime, borax). Suitable melting furnaces include bath smelting furnaces, top-blown converters, shaft furnaces, electric arc furnaces, and plasma furnaces. Furnaces can be operated in continuous or batch modes. The tapped alloy is typically subjected to an underwater atomizer, granulator, or casting mold (continuous or batch). The slag is typically fed to a slag cooling pool or underwater granulator, or atomized by a powerful gas stream into droplets that cool on their way to the ground.

[0054] Step (1.2) optionally subjects the reduced material to dry solid-solid separation such as electronic sorting, sieving or magnetic separation, or eddy current separation to remove solids such as carbon, polymers, magnetic materials or non-ferrous metals.

[0055] Step (1.3) is - optionally treating the reduced material with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material; - optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material; and - optionally subjecting the insoluble material to solid-solid separation to remove solids such as carbon, polymers, magnetic materials or insoluble lithium salts. is.

[0056] The slurry typically contains dissolved lithium salts such as LiOH, LiHCO3 and / or Li2CO3, or the Li salt of the acid used.

[0057] The solid-liquid separation can be filtration, centrifugation, sedimentation or decantation.

[0058] The aqueous medium should be capable of selectively dissolving the Li component without dissolving the transition metal. This treatment can be carried out at ambient temperature or at a higher temperature, for example, in the range of 20 to 150°C. When a temperature higher than the boiling point of water is used, this treatment is carried out at elevated pressure. Preferably, the aqueous medium contains a weak acid (e.g., carbonic acid, formic acid, acetic acid, or sulfurous acid) or a strong acid (e.g., sulfuric acid, hydrochloric acid, nitric acid), with weak acids being preferred. These acids are typically used in concentrations of 0.1 to 10% by weight in water, preferably 1 to 10% by weight. When using carbonic acid, it is preferred to use it under a carbon dioxide pressure of 10 to 150 bar. In one embodiment, the aqueous medium is water, for example, deionized water. In another embodiment, the reduced material is subjected to solid-liquid separation after the water treatment, e.g., filtration, and then treated first with water and then with a diluted weak acid. Both extracts may be kept separate to separate the various dissolved Li species. The duration of the treatment with the aqueous medium can be for a period ranging from 20 minutes to 10 hours, preferably from 1 to 8 hours. The ratio of aqueous medium to reduced material, by weight, can be in the range of 1:1 to 99:1, preferably 2:1 to 9:1.

[0059] Step (2) - Carbonylation of the reduced material Step (2.1) is the carbonylation of the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls, including nickel carbonyl and / or cobalt carbonyl-containing compounds.

[0060] The carbonylation can be achieved at a temperature of 30 to 300°C, preferably 70 to 250°C.

[0061] The carbonylation can be achieved at a pressure of from 1 to 300 bar, preferably from 50 to 300 bar.

[0062] Preferably, step (2.1) is a step of carbonylating the reduced material with carbon monoxide at a temperature of 70 to 250° C. and a CO partial pressure of 50 to 300 bar.

[0063] The reduced material to be carbonylated can be obtained from steps (1.1), (1.2) or (1.3).

[0064] The volatile carbonyls typically include Ni(CO), HCo(CO) and / or (NO)Co(CO). Preferably, the volatile carbonyls include Ni(CO), HCo(CO), or a mixture of Ni(CO), HCo(CO).

[0065] In addition to carbon monoxide, inert and / or reactive gases may be present during carbonylation.

[0066] The inert gas can be nitrogen, argon or carbon dioxide. The inert gas can be present at up to 90% by volume.

[0067] In a preferred form, where the reduced material contains mainly nickel and no or only small amounts of cobalt, an inert gas is present during carbonylation.

[0068] The reactive gas can be hydrogen or nitric oxide. The reactive gas can be present at up to 90% by volume. Preferably, the reactive gas is present when cobalt is present in the reduced material.

[0069] If the reduced material contains only small amounts of nickel (eg, up to 10, 5, or 1% by weight) or no nickel, a reactive gas may be present.

[0070] Carbonylating may be carried out in two or more steps under various conditions. In one form, nickel and cobalt are present in a reduced material, and the reduced material is first carbonylated in the absence of a reactive gas to form volatile nickel carbonyl, and then carbonylated in the presence of a reactive gas to form volatile cobalt carbonyl. In another form, nickel and cobalt are present in a reduced material, and the reduced material is first carbonylated in the presence of a reactive gas to form volatile cobalt carbonyl, and then carbonylated in the absence of a reactive gas to form volatile nickel carbonyl. Depending on the composition, it may be beneficial to repeat this process several times.

[0071] A carbonylation catalyst (such as ammonia, sulfur, or a sulfur compound such as hydrogen sulfide, carbon disulfide, or sulfur dioxide) may be present during carbonylation, in the absence or presence of a reactive gas.

[0072] In a preferred form where the reduced material contains predominantly nickel (e.g. at least 50, 70 or 90% by weight) and preferably no or only small amounts (e.g. less than 50, 20 or 10% by weight) of cobalt, a carbonylation catalyst may be present. The carbonylation catalyst may be added together with the carbon monoxide or the reduced material may be pre-treated with the carbonylation catalyst.

[0073] During both steps, any non-volatile carbonyls formed in the solid carbonylation residue can be decomposed by heating and / or releasing the pressure.

[0074] The reaction time for the carbonylation can be 1 hour to 4 days, preferably 1 hour to 2 days.

[0075] Step (3) - Separation and purification of volatile carbonyls Step (3.1) is the separation of volatile carbonyls from the solid carbonylation residue by evaporation.

[0076] The temperature during separation should be kept below the decomposition temperature and above the boiling point of the volatile carbonyl. For example, nickel tetracarbonyl is stable up to temperatures of approximately 180°C at ambient pressure, and cobalt tetracarbonyl hydride is stable from 110°C at 20 bar to 200°C at 300 bar carbon monoxide partial pressure.

[0077] Separation of volatile carbonyls may be carried out during the carbonylation in step (2.1). The pressure and gas composition in step (2.1) (e.g., partial pressure of carbon monoxide, inert gas, or hydrogen, or nitrogen oxides) are preferably selected so that separation can be carried out at the lowest possible temperature.

[0078] Step (3.2) is a step of optionally purifying the separated volatile carbonyl by adsorption, condensation, distillation or vaporization.

[0079] Volatile carbonyls can be condensed at temperatures below their respective boiling points, which depends on the applied pressure. From the condensed volatile carbonyls, the low-boiling carbonyl compounds can be obtained in pure form by distillation or as individual pure compounds, preferably by fractional distillation under a carbon monoxide-containing atmosphere.

[0080] The volatile carbonyls may also be adsorbed in organic solvents, water or aqueous media. Cobalt tetracarbonyl hydride can be absorbed in aqueous media such as alkali hydroxide solutions.

[0081] Step (3.2) can aid in the removal of undesired volatiles (eg, iron carbonyl) or the isolation of at least one of the volatile carbonyls, such as nickel carbonyl or cobalt carbonyl.

[0082] The solid carbonylation residue may be further processed, for example to recover residual transition metals. Suitable processing steps for the solid carbonylation residue are steps (3.3), (3.4) and / or (3.5).

[0083] Step (3.3) optionally involves decomposing non-volatile metal carbonyls in the solid carbonylation residue, which can be achieved by heating the solid carbonylation residue and / or by releasing pressure on the solid carbonylation residue.

[0084] Step (3.4) is a step in which the solid carbonylation residue is optionally subjected to dry solid-solid separation such as electrosorting, sieving or magnetic separation, and eddy current separation to remove solids such as carbon, polymers or magnetic materials.

[0085] Step (3.5) is - optionally treating the solid carbonylation residue with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material; - optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material; and - optionally subjecting the insoluble material to solid-solid separation to remove solids such as carbon, polymers, magnetic materials or insoluble lithium salts. is.

[0086] Optional Step (4) - Decomposition of Volatile Carbonyls Step (4.1) is an optional step of decomposing volatile carbonyls to produce nickel and / or cobalt in elemental form or as salts.

[0087] The volatile carbonyls to be decomposed can be obtained from steps (3.1) or (3.2).

[0088] Decomposition is typically carried out by heating the volatile carbonyls to above 180° C., preferably at low carbon monoxide partial pressures. Decomposition of the volatile carbonyls can be carried out as a mixture of nickel and cobalt carbonyls or after separation of both compounds.

[0089] Decomposition may also be achieved by converting the volatile carbonyls to nickel and / or cobalt sulfates by reaction with H2SO4, either by dissolution of the nickel and / or cobalt metals or oxides formed as intermediates.

[0090] Step (4.2.) is optionally a step of purifying the nickel and / or cobalt, for example by hydrometallurgy or by electrorefining. Preferably, the required metal purity is already achieved without carrying out step (4.2).

[0091] Other compounds can be recovered from the process of the invention: The lithium salt obtained as an aqueous solution from step (1.3) or (3.5) can be recovered by evaporating the water and crystallizing the lithium salt, which can be converted to another lithium salt, for example, by precipitation or decomposition.

[0092] The solid carbonylation residue obtained from step (2.1) can be subjected to a smelting furnace to recover mainly copper and iron, or the solid carbonylation residue can be subjected to a hydrometallurgical process in which the metals can be obtained as metal salt solutions, which can be subjected to further separation and purification steps such as precipitation, solvent extraction and / or electrowinning and electrorefining.

[0093] From the hydrometallurgical process, the carbon-based solid material (eg, graphite) can be isolated, purified, and used to produce electrodes for electrochemical processes or batteries.

[0094] The present invention offers several advantages: it allows for the recovery of high-value nickel and cobalt metals from batteries; it avoids hydrometallurgical processes, which require large amounts of acid and base and frequent solid-liquid separation steps; the conversion of the battery's nickel and cobalt constituent materials to volatile carbonyls is highly selective, forming only iron carbonyls, which can be easily separated, for example, by distillation; and copper impurities, among others, can be easily separated. [Example]

[0095] Instructions: The elemental composition is determined by elemental analysis using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectroscopy) or ICP-MS (Inductively Coupled Plasma-Mass Spectroscopy). Phase analysis was performed by powder X-ray diffraction (PXRD).

[0096] Abbreviation: In the context of the present invention, standard pressure means 1 atm or 1013 mbar. "Standard conditions" means standard pressure and 20°C. NI stands for normal liter, i.e., liter, at standard conditions (1 atm, 20°C). Percentages refer to mass % unless otherwise specifically defined. The expressions mass % (% by weight) and mass % (wt%) may be used interchangeably. When specified, the terms "room temperature" and "ambient temperature" refer to a temperature between about 18 and 25°C. XRD stands for powder x-ray diffraction (irradiation, typically Cu k-alpha 1 irradiation at 154 pm or Mo k-alpha 1 at 71 pm).

[0097] [Example 1] Heating of synthetic educt samples Nickel, cobalt, and manganese are added in similar molar amounts to the approximate formula Li(Ni0.34Co0.33Mn0.33)O2 78.8 g of used cathode active material containing 62.2g of carbon in the form of graphite and soot 47.0 g of organic electrolyte mixture (containing LiPF6) 7.4 g of polyvinylidene fluoride as a binder 2.4g aluminum powder 0.2g of iron powder 2.0g copper metal A 200 g quantity of simulated spent battery waste containing Ni / Co alloy was placed in a 500 mL quartz round-bottom flask and attached to a rotary evaporator so that the flask was immersed in the oven. Within 4.5 hours, the rotating flask was heated to 800 °C over 2 hours under a flow of argon (20 L / h), held at this temperature for 1 hour under a flow of dry air (20 L / h), and then cooled to ambient temperature. A quantity of 173.3 g of heat-treated material was obtained, with a phase composition consisting of Ni / Co alloy, iron-manganese oxide, and graphite.

[0098] Example 1a: Heating of a Lithium-Ion Battery Approximately 1 ton of mechanically processed battery scrap containing spent cathode active material containing nickel, cobalt, and manganese, organic carbon in the form of graphite and soot, and residual electrolyte, as well as additional impurities including fluorine compounds, phosphorus, and calcium, was treated to obtain reduced material according to the process described in Jia Li et al., Journal of Hazardous Materials, Vol. 302 (2016), pp. 97-104. The atmosphere inside the roasting system was air, the oxygen of which reacted with the carbon in the battery scrap to form carbon monoxide, and the treatment temperature was 800°C.

[0099] After reaction and cooling to ambient temperature, the heat-treated material is recovered from the furnace and mechanically processed to obtain a particulate material that is analyzed by X-ray powder diffraction and elemental analysis.

[0100] The Ni and Co contents were determined to be 17.7 and 17.5 mass-%, respectively, and these serve as references for all further carbonylation examples (see below).

[0101] Comparing the XRD patterns before and after heat treatment with calculated reference patterns for Li(Ni,Co,Mn)O2, Ni (which is identical to that of CoxNi1-x (x = 0-0.6)), and Co, it can be concluded that the cathode active material is completely decomposed and that Ni and Co exist exclusively as metallic phases, either as pure Ni or as an alloy combined with Co. The presence of nickel and cobalt metals is supported by the qualitative observation that the entire sample exhibits typical ferromagnetic behavior when in contact with a permanent magnetic material.

[0102] [Example 2] Carbonylation of synthetic educt samples with CO and H2 1 g of a 50 / 50 mixture of Co and Ni powder is charged into an autoclave and reacted with CO and H2 at 170 °C and 200 bar. The respective gas flows are 15 Nl / h for both CO and H2. After a reaction time of 10 h, the autoclave is filled with nitrogen and cooled. The solid residue is isolated, weighed (0.5 g), and analyzed for its Ni and Co content (Ni: 3 wt.-%, Co: 96 wt.-%), which corresponds to a recovery of Ni and Co from the volatiles of 97% and 4%, respectively.

[0103] Example 2a: Carbonylation of reduced material with CO and H2 at 170°C / 200 bar 1 g of the above reduced battery waste material (obtained as shown in Example 1a, Ni content 17.7%, Co content 17.5%) is loaded into an autoclave and reacted with CO and H at 170 °C and 200 bar. The respective gas flows are 15 Nl / h for both CO and H. After a reaction time of 10 h, the autoclave is filled with nitrogen and cooled. The solid residue is isolated, weighed (0.88 g) and analyzed for its Ni and Co content (Ni: 15.4 wt.-%, Co: 16.1 wt.-%), which corresponds to a recovery of Ni and Co from the volatiles of 23% and 19%, respectively.

[0104] Example 2b: Carbonylation of reduced material with CO and H2 at 200°C / 200 bar Example 2a is repeated applying 200°C and 200 bar, keeping all other experimental conditions constant. 0.88 g of solid residue is isolated and analyzed for its Ni and Co content (Ni: 16.5 wt-%, Co: 17.2 wt-%), which corresponds to a recovery of Ni and Co of 18% and 14%, respectively.

[0105] [Example 3] Carbonylation of suspensions of Ni powder in dodecane with CO. 1 g of nickel powder is mixed with 70 mL of dodecane, charged into a stirred autoclave, and reacted with 15 Nl CO at 150 °C and 200 bar for 8 h. This procedure is carried out twice. After these two reactions, the autoclave is filled with nitrogen, cooled, and opened. It is observed that most of the nickel powder can no longer be seen, and it is concluded that the carbonylation reaction and evaporation have been successfully completed.

[0106] Example 3a: Carbonylation of a suspension of Co powder in dodecane with CO and H 1 g of cobalt powder is mixed with 70 mL of dodecane, loaded into a stirred autoclave, and reacted with 15 Nl of CO and H at 170 °C and 200 bar for 8 h, respectively. To capture volatile Co carbonyl species, the gas stream is directed into a NaOH solution (10%). This solution is analyzed for its Co content and used to quantify the Co recovery, which is 1%. After the reaction, the autoclave is filled with nitrogen, cooled, and opened.

[0107] Example 3b: Carbonylation of a suspension of reduced material in dodecane with CO and H 0.5 g of the above reduced battery waste material (obtained as shown in Example 1a, Ni content 17.7%, Co content 17.5%) is mixed with 70 mL of dodecane, charged into a stirred autoclave, and reacted with CO and H2 under various experimental conditions (see Table 1). To capture volatile Co carbonyl species, the gas stream is directed into a NaOH solution (10%). This solution is analyzed for its Co content and used to quantify the Co recovery. This solution is not changed between each experiment. The results are also summarized in Table 1.

[0108] [Table 1]

Claims

1. 1. A method for recovering transition metals from battery materials, comprising: (0.1) providing a battery material containing a nickel oxide and / or cobalt oxide compound; (1.1) heating the battery material to above 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls, including nickel carbonyl and / or cobalt carbonyl-containing compounds; and (3.1) Separating volatile carbonyls from the solid carbonylation residue by evaporation Including, the volatile carbonyls comprise a mixture of Ni(CO) 4 and HCo(CO) 4 ; method.

2. The method of claim 1 , wherein the battery material is a lithium ion battery material.

3. 3. The method of claim 1 or 2, wherein the battery material comprises finished batteries, mechanically processed waste batteries, or battery scrap, or scrap from the manufacture of batteries or battery components.

4. 4. The method according to claim 1, wherein the battery material contains 1 to 30% by weight of the nickel oxide compound.

5. 4. The method according to claim 1, wherein the battery material contains 1 to 30% by weight of the cobalt oxide compound.

6. 6. The method according to any one of claims 1 to 5, wherein step (1.1) is carried out by heating the battery material in an inert atmosphere or a hydrogen atmosphere.

7. 7. A process according to any one of claims 1 to 6, wherein the carbonylation is effected at a temperature of from 30 to 300°C and a pressure of from 100 to 30,000 kPa (1 to 300 bar).

8. 8. The process of any one of claims 1 to 7, wherein in addition to carbon monoxide, an inert gas and / or a reactive gas is present during the carbonylation.

9. 9. The method of claim 8, wherein the inert gas is nitrogen, argon, or carbon dioxide.

10. 9. The method of claim 8, wherein the reactive gas is hydrogen or nitric oxide.

11. 11. A process according to any one of claims 1 to 10, wherein a carbonylation catalyst selected from ammonia, sulfur or a sulfur compound is present during the carbonylation.

12. 12. The method of any one of claims 1 to 11, wherein nickel and cobalt are present in a reduced material, and the reduced material is first carbonylated in the absence of a reactive gas to form volatile nickel carbonyl, and then carbonylated in the presence of a reactive gas to form volatile cobalt carbonyl.

13. (4.1) Decomposing the volatile carbonyls to produce nickel and / or cobalt in elemental form or as salts.

13. The method of any one of claims 1 to 12, further comprising:

14. The following steps (0.2), (0.3), (0.4), (0.5), (1.2), (1.3), (3.2), (3.3), (3.4), (3.5) and (4.2): (0.1) providing a battery material containing a nickel oxide and / or cobalt oxide compound; (0.2) optionally washing the battery material with an organic solvent to remove the organic electrolyte and polymer binder; (0.3) optionally washing the battery material with an aqueous medium; (0.4) optionally subjecting the battery material to solid-solid separation to remove solids; (0.5) optionally, heating the battery materials up to 350°C to evaporate the organic components of the electrolyte; (1.1) heating the battery material to above 350°C to produce a reduced material containing nickel and / or cobalt in elemental form; (1.2) optionally subjecting the reduced material to dry solid-solid separation to remove solids; (1.3) optionally treating the reduced material with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material, optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material, and optionally subjecting the insoluble material to solid-solid separation to remove solids; (2.1) carbonylating the reduced material with carbon monoxide, optionally in the presence of a reactive gas, to produce a solid carbonyl residue and volatile carbonyls, including nickel carbonyl and / or cobalt carbonyl-containing compounds; (3.1) Separating volatile carbonyls from the solid carbonylation residue by evaporation; (3.2) optionally purifying the separated volatile carbonyls by adsorption, condensation, distillation or vaporization; (3.3) optionally decomposing non-volatile metal carbonyls in the solid carbonylation residue; (3.4) optionally subjecting the solid carbonylation residue to dry solid-solid separation to remove solids; (3.5) optionally treating the solid carbonylation residue with an optionally acidic aqueous medium to produce a slurry containing dissolved lithium salts and insoluble material, optionally subjecting the slurry to solid-liquid separation to separate the dissolved lithium salts from the insoluble material, and optionally subjecting the insoluble material to solid-solid separation to remove the solids; (4.1) decomposing the volatile carbonyl to produce nickel and / or cobalt in elemental form or as salts; and (4.2) Optionally, further purifying the nickel and / or cobalt The method according to any one of claims 1 to 13, comprising at least one of:

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